DESCRIPTION: (From investigator's abstract) The application organization has completed design and programming for a microcomputer software system providing personal self-administered risk assessment for HIV infection. The risk assessment is based upon an anonymous interactive interview and analysis performed by a rule-based expert system incorporated in the software. The purpose of this proposal is to support revision and expansion of the software to accommodate simultaneous risk assessment for chlamydia trachomatis, the most prevalent sexually transmissible disease in the nation. The system will not require respondents to possess specialized training or computer experience. Following analysis of an individual's personal history taken by the interactive interview, the completed software will respond with advice as to whether the respondent is at risk for HIV and/or chlamydia trachomatis and will also write anonymous case data to DOS files for interface with statistical software.